Sturm, Ruger & Company, Inc. has expanded the Ruger Mark IV 22/45 Lite family of rimfire pistols with a new model that features a mounting position for a standard Shield RMS footprint reflex optic in place of the Picatinny rail. It also features a raised front fiber optic sight and an adjustable rear sight that co-witness with most micro red dot optics. The new model has an attractive ventilated rib on top of a clear anodized receiver.